updated pycrypto

modules/Crypto/Hash/hashalgo.py

@@ -0,0 +1,116 @@
+# -*- coding: utf-8 -*-
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain.  To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+from binascii import hexlify
+
+class HashAlgo:
+    """A generic class for an abstract cryptographic hash algorithm.
+    
+    :undocumented: block_size
+    """
+
+    #: The size of the resulting hash in bytes.
+    digest_size = None
+    #: The internal block size of the hash algorithm in bytes.
+    block_size = None
+
+    def __init__(self, hashFactory, data=None):
+        """Initialize the hash object.
+
+        :Parameters:
+         hashFactory : callable
+            An object that will generate the actual hash implementation.
+            *hashFactory* must have a *new()* method, or must be directly
+            callable.
+         data : byte string
+            The very first chunk of the message to hash.
+            It is equivalent to an early call to `update()`.
+        """
+        if hasattr(hashFactory, 'new'):
+            self._hash = hashFactory.new()
+        else:
+            self._hash = hashFactory()
+        if data:
+            self.update(data)
+
+    def update(self, data):
+        """Continue hashing of a message by consuming the next chunk of data.
+        
+        Repeated calls are equivalent to a single call with the concatenation
+        of all the arguments. In other words:
+
+           >>> m.update(a); m.update(b)
+           
+        is equivalent to:
+        
+           >>> m.update(a+b)
+
+        :Parameters:
+          data : byte string
+            The next chunk of the message being hashed.
+        """
+        return self._hash.update(data)
+
+    def digest(self):
+        """Return the **binary** (non-printable) digest of the message that has been hashed so far.
+
+        This method does not change the state of the hash object.
+        You can continue updating the object after calling this function.
+        
+        :Return: A byte string of `digest_size` bytes. It may contain non-ASCII
+         characters, including null bytes.
+        """
+        return self._hash.digest()
+
+    def hexdigest(self):
+        """Return the **printable** digest of the message that has been hashed so far.
+
+        This method does not change the state of the hash object.
+        
+        :Return: A string of 2* `digest_size` characters. It contains only
+         hexadecimal ASCII digits.
+        """
+        return self._hash.hexdigest()
+
+    def copy(self):
+        """Return a copy ("clone") of the hash object.
+
+        The copy will have the same internal state as the original hash
+        object.
+        This can be used to efficiently compute the digests of strings that
+        share a common initial substring.
+
+        :Return: A hash object of the same type
+        """
+        return self._hash.copy()
+
+    def new(self, data=None):
+        """Return a fresh instance of the hash object.
+
+        Unlike the `copy` method, the internal state of the object is empty.
+
+        :Parameters:
+          data : byte string
+            The next chunk of the message being hashed.
+
+        :Return: A hash object of the same type
+        """
+        pass
+